Scientists have traced mysterious radio waves to a dwarf galaxy more than three billion light years away.

The first "fast radio burst" (FRB) was discovered 10 years ago and they have baffled astronomers ever since.

The powerful but very short-lived bursts of radio waves - lasting no more than a millisecond - have been difficult to track.

Now, scientists at McGill University in Montreal and New York's Cornell University have used the Very Large Array - a multi-antenna telescope in New Mexico - to determine the exact location of the flash, known as FRB 121102.

Their findings have been published in the science journal Nature and presented at the American Astronomical Society's annual conference in Texas.

Astronomers studied nine bursts from the FRB for six months and were able to hone in on their exact position in the cosmos.